Each Alignak daemon can be configured to load and use modules. In the daemon configuration file, the attribute modules may contain a list of the daemon modules.

As a default, no module is installed nor configured but one can edit the daemon configuration file to declare which module is to be used. The modules property is a comma separated list of the declared modules alias.

To achieve this, the Receiver daemon needs to be extended with an NSCA module. This module listens on a TCP port for NSCA packets, decode the packets and builds an external command corresponding to the received check: HOST_PASSIVE_CHECK or SERVICE_PASSIVE_CHECK.

This module allows Alignak framework (like Nagios and al.) to reacts to external commands sent to a named pipe file.

Thanks to this module the receiver daemon periodically reads the content of a configured file and builds an external command with the information read from this file. This also allows Alignak to receive passive checks.

Note that the Arbiter is able to manage the external commands by itself and that it is not necessary to use an external module…